@inproceedings{10.1109/SC41406.2024.00023, author = {Devarajan, Hariharan and Pottier, Lo\"{\i}c and Velusamy, Kaushik and Zheng, Huihuo and Yildirim, Izzet and Kogiou, Olga and Yu, Weikuan and Kougkas, Anthony and Sun, Xian-He and Yeom, Jae Seung and Mohror, Kathryn}, title = {DFTracer: An Analysis-Friendly Data Flow Tracer for AI-Driven Workflows}, year = {2024}, isbn = {9798350352917}, publisher = {IEEE Press}, url = {https://doi.org/10.1109/SC41406.2024.00023}, doi = {10.1109/SC41406.2024.00023}, abstract = {Modern HPC workflows involve intricate coupling of simulation, data analytics, and artificial intelligence (AI) applications to improve time to scientific insight. These workflows require a cohesive set of performance analysis tools to provide a comprehensive understanding of data exchange patterns in HPC systems. However, current tools are not designed to work with an AI-based I/O software stack that requires tracing at multiple levels of the application. To this end, we developed a data flow tracer called DFTracer to capture data-centric events from workflows and the I/O stack to build a detailed understanding of the data exchange within AI-driven workflows. DFTracer has the following three novel features, including a unified interface to capture trace data from different layers in the software stack, a trace format that is analysis-friendly and optimized to support efficiently loading multi-million events in a few seconds, and the capability to tag events with workflow-specific context to perform domain-centric data flow analysis for workflows. Additionally, we demonstrate that DFTracer has a 1.44x smaller runtime overhead and 1.3-7.1x smaller trace size than state-of-the-art tracing tools such as Score-P, Recorder, and Darshan. Moreover, with AI-driven workflows, Score-P, Recorder, and Darshan cannot find I/O accesses from dynamically spawned processes, and their load performance of 100M events is three orders of magnitude slower than DFTracer. In conclusion, we demonstrate that DFTracer can capture multi-level performance data, including contextual event tagging with a low overhead of 1-5\% from AI-driven workflows such as MuMMI and Microsoft's Megatron Deepspeed running on large-scale HPC systems.}, booktitle = {Proceedings of the International Conference for High Performance Computing, Networking, Storage, and Analysis}, articleno = {17}, numpages = {24}, keywords = {I/O, application apis, deep learning, interception, multilevel, system calls, tracer, transparent, workflows}, location = {Atlanta, GA, USA}, series = {SC '24} }